1. Technical Field
The present disclosure relates to a sheet feeding device having a mechanism that removes a sheet of media from a feed roller, that feeds sheets of media such as recording paper, and to a printer having the sheet feeding device.
2. Related Art
The inventors have noticed that an example of such a sheet feeding device is the paper supply device of a printer. In this example, recording paper is held in a stack in a cassette and is pressed against a paper supply roller (e.g., a feeding roller). When the paper supply roller turns, the recording paper is fed sequentially from the top sheet in the stack to the paper feed path inside the printer. The sheet support member that supports the stacked recording paper in the cassette is called a hopper plate, for example. The hopper plate is pushed toward the paper feed roller by a spring member, and the stacked recording paper is pressed against the paper feed roller regardless of the number of sheets in the stack.
The inventors have noticed an operation that separates recording paper from the paper feed roller may also be performed in this paper supply device. In this event, the hopper plate is forcibly pushed in the direction away from the paper supply roller after the recording paper is advanced a specific amount and passed to a downstream separating mechanism. The recording paper feeding operation and the operation separating the recording paper from the paper feed roller are executed alternately each time the paper feed roller turns one revolution. JP-A-2006-137564 discloses a sheet feeding device that alternately performs a feeding operation and a separating operation.
The inventors have noticed that a sheet feeding device disclosed in JP-A-2006-137564 has a depressing mechanism that pushes a middle plate (hopper plate) down. The rotation of a paper feed cam that rotates in conjunction with the paper feed roller in this mechanism pushes a depressing arm down pivoting on a pivot point. When the depressing arm is pushed down, a depressing claw inside the depressing arm extends straight out, and engages a middle plate claw disposed on the middle plate side. The middle plate is then also pushed down when the depressing arm descends, and the sheets stacked on the middle plate separate from the paper feed roller. Because the depressing claw extends through a wide range in the sheet stacking direction, the depressing claw can be engaged with the middle plate claw even when the position of the middle plate changes according to the number of stacked sheets.
For example, the inventors have noticed that the depressing mechanism disclosed in JP-A-2006-137564 has a depressing claw that can slide in a straight line in the depressing arm that pivots with rotation of a paper feed cam. The mechanism for moving the depressing claw in and out in conjunction with the depressing action of the depressing arm is also disposed between the depressing arm and the depressing claw.